1910.] 



NATURAL SCIENCES OF PHILADELPHIA. 



79 



Cave Creek (cataracta). The lower line Is a similar but independent 

 chain from the southern canyons, a considerable distance from the 

 nearest of the more northern group. 



From Big Emigrant Canyon to Shake Gulch the Stations mentioned 

 above run in a general direction from northwest to southeast. From 

 the emigrans station to Onion Creek station is about 16 miles; 

 thence to Cave Creek, 4; to Cave Creek Falls (var. cataracta), 2; to 

 Rucker Box, 12; to Shake Gulch, 12. Total, 44 miles as the crow 

 flies; but it is 55 by trail. 



One peculiarity runs throughout the entire clappi series: they are 

 hard to catch. Except at Onion Creek the} r were grouped in small 

 families and the families did not seem to be upon speaking terms. 

 They were clannish and confined their travels to one particular rock 

 slide. In only two instances was the same form found in two slides of 

 rock, though the rocks were well explored for miles around. At Onion 

 Creek they were plentiful; about 100 were collected there in an hour. 

 Oreohelix clappi emigrans n. subsp. 



This shell is similar in outline to 0. clappi, but more sharply angular 

 at the periphery, or even carinate in front. Cuticle thicker, rough, 

 usually persistent, dark olive brown in color, lusterless, not banded, 

 coated and caked with a deposit of humus. The sculpture after the 

 embryonic shell consists of oblique, uneven, rather sharp striae, and 



Fig. 7. — Oreohelix clappi emigrans. 



on the last whorl some coarse wrinkles. The striae are sharper than 

 in 0. clappi and close together up to the last whorl; on the base they 

 are thread-like, crimped and waved at the intersections of four or five 

 circular rows of short cuticular appendages, which are usually retained 

 only on the latter part of the base. In immature shells the thread- 

 like striae are surmounted by delicate cuticular laminae, more or less 

 felted together by the adhering dirt. The aperture is rounded- 



